African Journal of Laboratory Medicine最新文献

Background: Chronic lymphocytic leukaemia (CLL) is a haematological neoplasm with characteristic flow cytometric immunophenotyping. Pre-analytical variables impact the quality and reproducibility of flow cytometric data, which could alter the diagnosis from CLL to atypical CLL (aCLL).

Objective: This study investigated the effects of pre-analytical variables, specifically sample age and storage temperature, on the stability of key antigens used in the diagnosis of CLL.

Methods: Serial flow cytometric analyses were performed from January 2022 to March 2023 on blood samples of 10 CLL patients from the Universitas Academic Hospital Haematology Clinic in Bloemfontein, South Africa. Samples were stored at room and refrigerator temperatures and analysed at baseline, 24 h, 48 h, 72 h and 96 h. We recorded the percentage and intensity of antigen expression of CLL makers, including CD5, CD20, CD23, CD79b, CD200 and sIgM, and assessed whether these affected the adapted and modified Matutes scores.

Results: Statistically significant changes were observed in CD5 (p = 0.028), CD23 (p = 0.003) and CD200 (p = 0.005) expression, with better stability at refrigerator temperature. Two samples showed changes in both Matutes scores by 24 h, irrespective of storage temperature. By 48 h, scores changed to aCLL in six room-temperature and four refrigerated samples. A majority shift in diagnosis to aCLL (modified Matutes: n = 8/10; adapted Matutes: n = 7/10) was observed at 96 h for refrigerated samples.

Conclusion: These findings indicate that pre-analytical variables influence antigen stability in CLL samples, with better preservation at refrigerator temperature, recommending analysis within 48 h of collection.

What this study adds: This study highlights the impact of pre-analytical variables on the flow cytometric diagnosis of CLL. Extended room temperature storage alters antigen expression, shifting Matutes scores and potentially affecting the final diagnosis. The findings emphasise optimised sample handling, for improved diagnostic accuracy in laboratory medicine.

Continuous professional development (CPD) represents a cornerstone in the advancement of professional skills and knowledge across various sectors. It is globally recognised as a transformative process that unlocks potential, increases capacity, and fosters personal growth. This narrative review article aimed to understand how the CPD training programmes for laboratory professionals are implemented and sustained in Africa. A narrative review was conducted where a comprehensive search was conducted across PubMed, Embase, and web searches for white and/or grey literature, facilitated by a custom Python script. A combination of keywords, truncations, and subject headings targeted four key themes: Continuing professional development (and related terms), laboratory professionals, African countries, and aspects of implementation and scoring. The search was restricted to articles in English published from 2009 to 2024. While the actual training needs and gaps for CPD programmes are widely known, the actual implementation of CPD has remained a challenge. In the past, CPD training programmes have been implemented to address the lack of skills and the insufficient and skewed distribution of these health workers. This approach is not sustainable and has led to some challenges with coordination, quality assurance, and regulation. Each country has its unique context and training needs; therefore, CPD needs to be more coordinated and tailored so that professionals are given the right training for their needs.

What this study adds: Addressing training gaps for laboratory professionals in Africa will require a well-structured, coordinated and tailored approach that will deliver a continent-wide CPD programme.

Background: Laboratories and diagnostics services are critical to universal health coverage and public health response. We assessed the extent of the implementation and functionality of the 2016-2023 Eastern Mediterranean Region (EMR) laboratory strategic framework.

Intervention: Documents and reports from World Health Organization country offices were examined between September 2022 and November 2022, supplemented by stakeholder-provided documents, to enhance data collection and reporting across the framework's five goals. An intervention using a performance evaluation scorecard assessed the progress of EMR Member States (MSs) towards strengthening health laboratory services, with findings validated during the December 2022 regional public health laboratory directors' meeting in Egypt.

Lessons learnt: We analysed results from 21 of 22 MSs. Three (14%) MSs, all high income, had the capacity to implement all indicators, while only one of five low-income (20%) MSs could not demonstrate any capacity across all five goals evaluated. Irrespective of income category, the least implemented domains were: (1) availability of either or both fully implemented laboratory policy, and (2) a fully implemented integrated national laboratory strategic plan, both of which were implemented in only 50% of MSs.

Recommendations: Addressing the identified gaps requires concerted efforts, collaboration, and sustained investment to ensure the delivery of high-quality laboratory services and advance public health outcomes across the EMR. Implementation of laboratory strategies should be coordinated through the specific laboratory department or unit at the Ministry of Health level, above the central public health laboratories and with the support of a national laboratory technical working group.

What this study adds: This study revealed substantial gaps in implementing laboratory policies and strategic plans in the EMR, with full implementation achieved by only 50% of MSs. It underscores the necessity for coordinated efforts and sustained investment to enhance laboratory services and promote effective laboratory practices in EMR.

Background: The National Health Laboratory Service was using Becton Dickinson (BD) blood drawing tubes and, in 2021, the supplier notified customers of supply challenges, indicating a risk of global shortages.

Objective: This study aimed to validate candidate blood collection tubes from four brands (VACUCARE, VACUETTE^®, VACUTEST^®, and V-TUBE^™) compared to BD Vacutainer^® tubes in three National Health Laboratory Service laboratories in Cape Town, South Africa.

Methods: Blood was collected from 300 healthy volunteers between October 2021 and November 2021. The technical validation assessed 11 quality indicators, with a sigma metric greater than 4 deemed acceptable. Usability feedback was gathered from phlebotomists. The clinical validation estimated differences in results across 52 clinical chemistry tests, using desirable bias specified by the European Federation of Clinical Chemistry and Laboratory Medicine Biological Variation Database, or Ricos, as acceptance criteria. Analysis was performed on Roche cobas^® 6000 and DiaSorin Liaison^® XL analysers.

Results: All VACUCARE tubes exhibited sigma metrics above 4, indicating excellent performance. VACUETTE^® and V-TUBE^™ were not uncapped by all Roche pre-analytical systems. VACUTEST^® caps had rigid rubber, making it more challenging to puncture and detach the tube, which resulted in needle displacement. Both VACUCARE and V-TUBE^™ were reported as user-friendly. All candidate tube analytes showed acceptable clinical performance.

Conclusion: VACUCARE, VACUETTE^®, VACUTEST^® and V-TUBE^™ are viable alternatives to BD Vacutainer^®. However, based on the results obtained from the technical validation, VACUCARE was identified as the most suitable interim replacement for BD Vacutainer^® during the shortage.

What this study adds: This study addresses a gap in the literature on tube validation and provides valuable insights for clinical laboratories considering a replacement. It also presents an alternative approach to technical validation by utilising sigma metrics.

Background: Vaginal trichomoniasis is a highly prevalent parasitic infection associated with HIV acquisition and preterm birth. The 'gold standard' for its diagnosis requires 3-7 days to detect by culture. Rapid and accurate diagnosis, such as by nucleic acid amplification testing, is key to manage the disease, and control and prevent its transmission.

Aim: This review aimed to assess the overall accuracy of real-time polymerase chain reaction (RT-PCR)-based assays, for routine diagnosis of Trichomonas vaginalis in clinical vaginal samples from women with symptomatic/asymptomatic trichomoniasis, using Trichomonads culture as the gold standard.

Methods: MEDLINE, PubMed, EMBASE, and other sources were used to search for included studies published between 01 January 1995 and 31 July 2023. The search terms 'real-time polymerase chain reaction', 'real-time', 'polymerase chain reaction', 'Trichomonas vaginalis', 'trichomonas', 'vaginalis', 'humans', 'rt pcr', 'nucleic acid amplification test', 'NAAT', 'trichomonad culture', 'women' were included. Summary estimates were calculated for the overall accuracy of the assay compared to Trichomonads culture as the reference standard. Meta-analysis was conducted using a bivariate meta-regression model.

Results: Twenty-seven eligible studies met our inclusion criteria: sensitivity 99% (95% confidence interval [CI] 99-100), specificity 100% (95% CI 100-100), positive likelihood ratio 350.67 (167.42-734.49), negative likelihood ratio 0.02 (0.01-0.03), diagnostic odds ratio 23 064.05 (95% CI 8532.13-62 346.77), and area under receiver operating characteristics curve 0.99. There was significant heterogeneity in sensitivity and specificity (p < 0.001).

Conclusion: Our results suggested that RT-PCR assays could be useful for the diagnosis of vaginal trichomoniasis with high sensitivity and specificity.

What this study adds: This article provides a comprehensive review of the effectiveness of RT-PCR assays for the diagnosis of trichomoniasis with high sensitivity and specificity in comparison to other methods in clinical laboratory practice. The goal is to present awareness/evidence that this assay is more accurate and rapid than other techniques.

Background: Menorrhagia, characterised by menstrual blood loss exceeding 80 mL per cycle, is a common issue in Western Kenya. However, there are insufficient data on how hormonal disorders contribute to its occurrence.

Objective: This study aimed to examine the differences and associations between thyroid and reproductive hormone levels in women with menorrhagia versus those without, in Bungoma County, Kenya.

Methods: A comparative cross-sectional study was conducted among 428 women (214 with menorrhagia and 214 controls) aged 18-45 years, between 01 December 2022 and 31 September 2023 at Bungoma County Referral Hospital. The analysis included thyroid stimulating hormone, total and free triiodothyronine, thyroxine, follicle stimulating hormone (FSH), luteinising hormone, prolactin, oestrogen, progesterone, and testosterone.

Results: Women experiencing menorrhagia had statistically significant increases in levels of FSH (p < 0.0001), oestrogen (p < 0.001), and total testosterone (p < 0.001), while prolactin levels had a statistically significant decrease (p < 0.001) compared to those without menorrhagia. There were no statistically significant differences in total triiodothyronine (p = 0.384), free triiodothyronine (p = 0.610), total thyroxine (p = 0.127), free thyroxine (p = 0.360), or thyroid stimulating (p = 0.118). No associations were found between menorrhagia and either thyroid or reproductive hormones.

Conclusion: Elevated levels of FSH, oestrogen, and testosterone, along with reduced prolactin, may serve as potential biomarkers for diagnosing menorrhagia in premenopausal or reproductively aged women. A screening tool that integrates these hormonal markers could improve the accuracy of diagnosis and optimise treatment strategies in primary healthcare settings.

What this study adds: The study suggests that levels of FSH, oestrogen, total testosterone, and prolactin differ significantly between women with and without menorrhagia, indicating their potential use in predicting the condition.

Background: Monoclonal gammopathies, including multiple myeloma, present significant challenges in sub-Saharan Africa. Diagnosis is often missed because of limited screening tools. The gamma gap and albumin-globulin ratio (AGR) have been proposed as simple, cost-effective screening methods; however, their utility in settings with prevalent infectious and inflammatory diseases is unclear.

Objective: This study evaluated the diagnostic accuracy of gamma gap and AGR in identifying patients who require further investigation for monoclonal gammopathies in South Africa.

Methods: A retrospective analysis of 7946 patients who underwent investigations for monoclonal gammopathies at Groote Schuur Hospital, South Africa, between September 2015 and September 2022 was conducted. Patients were classified based on monoclonal protein detection, and the gamma gap, AGR, and multivariable models were evaluated for diagnostic performance.

Results: Among the patients (median age: 61 years, 58% female [4632/7946] and 42% [3314/7946] male patients), 1231 had monoclonal proteins. A gamma gap cutoff of 46 g/L identified 35% of monoclonal cases (sensitivity), with 91% specificity and an area under the curve (AUC) of 0.60. The AGR showed a slightly better AUC of 0.63, with 44% sensitivity and 80% specificity at a 0.85 cutoff. Multivariable models incorporating age, sex, and hypogammaglobulinaemia improved performance, with the gamma gap model achieving an AUC of 0.73, improving the sensitivity to 58%, with a specificity of 78%.

Conclusion: The gamma gap and AGR showed low sensitivity and moderate specificity in screening for monoclonal gammopathies, highlighting the need for integrated diagnostic approaches combining clinical, demographic, and laboratory data to improve early detection in resource-limited settings.

What this study adds: Although cost-effective and widely available, gamma gap and AGR have limited accuracy for screening monoclonal gammopathies when used alone in settings with prevalent infectious and inflammatory diseases. Although the tests are good at ruling out monoclonality, they risk missing many true cases, delaying diagnosis and treatment.